With concern increasing in the U.S. to understand how to decrease the burden of disability associated with aging, we have been conducting a study to define older women at risk of disability and the causes of disablement. This study is conducted with support of space and personnel from the OPD-GCRC and through an investigator-initiated RO1 from the National Institute on Aging entitled "Risk Factors for Physical Disability in Aging Women". The study, referred to as the Women's Health and Aging Study II (WHAS II), is a prospective, observational study of a cohort of 436 women 70-79 years of age at baseline, to determine the characteristics of early functional decline, termed "preclinical disability", the risk factors and underlying causes of preclinical disability and progression to disability and dependency, and whether early decrements in physical functioning are predictive of future disability.